As research supporting the use of prophylactic mesh to prevent incisional hernia continues to grow, the focus of managing that surgical complication may change from treatment to prevention. The key to shifting this pendulum is identifying the right patients. Are we there yet?

“I will caveat the answer with ‘we’re working on it and we’re close,’” said William Hope, MD, the program director of the general surgery residency program at the Novant/New Hanover Regional Medical Center, in Wilmington, N.C., speaking at the 2021 virtual Abdominal Wall Reconstruction Conference.

When the European Hernia Society (EHS) published its recommendation on prophylactic mesh augmentation (PMA) in 2015 (the latest to date), there weren’t enough data from sufficiently large trials for the society to strongly support the use of PMA in all patients meeting the criteria for particular risk groups. Since then, things have changed.

A year later, researchers led by Filip Muysoms, MD, in Belgium reported the findings of a randomized controlled trial of 120 patients with abdominal aortic aneurysms. At two years’ follow-up, the incisional hernia rate in patients who underwent primary suturing was 28%, while none of the patients with a PMA (recto-rectus, large-pore PPE) developed an incisional hernia (Ann Surg 2016;263[4]:638-645).

“This is probably the easiest high-risk group to identify, and I think we would all agree on PMA in patients with abdominal aortic aneurysms,” Dr. Hope said.

This was followed by the PRIMA trial, which included two groups of high-risk patients—those with abdominal aortic aneurysms and those with obesity (body mass index =27 kg/m²)—as well as two mesh placement techniques, onlay and sublay (Lancet 2017;390[10094]:567-576).

“They reported that you definitely decrease the chance of an incisional hernia by placing a mesh. This was really the first time this was shown with an onlay, and at least in prophylaxis, the onlay did as well as the sublay,” Dr. Hope said.

Mesh has also been investigated in the setting of parastomal hernia prevention. In 2018, the EHS recommended use of prophylactic synthetic nonabsorbable mesh on construction of the end colostomy. “This was a strong recommendation based on a lot of data,” Dr. Hope said.

A follow-up systematic review and meta-analysis that found PMA reduced the risk for incisional hernia after stoma reversal further supported the EHS’s recommendation (Hernia 2019;23[4]:733-741).

Still, among the surgical interventions aimed at preventing incisional hernia (e.g., using minimally invasive techniques, minimizing potential wound complications and using optimal suturing techniques), PMA is the most controversial: placing mesh to prevent an outcome that hasn’t happened.

“The risk–benefit has to be carefully considered and balanced,” John Fischer, MD, told General Surgery News. “It’s similar to the dilemma we face in hernia repair: We know there’s a risk of recurrence if we don’t use mesh to support the repair, but we’re also putting mesh into patients who won’t develop a recurrence.”

Another reason PMA is controversial is that much of the data supporting its use come from European trials, and it’s not certain that the findings of those trials are applicable to patients in the United States.

“The PRIMA trial shows a nice benefit to using mesh, but those patients really aren’t the same as the patients we see. We had the same issue with the STITCH trial, which showed the benefit of closing with very small bites and lots of suture: Is it generalizable?” said Dr. Fischer, an associate professor of surgery at the University of Pennsylvania, in Philadelphia.

Also worth noting is that no mesh has been indicated for use as a prophylactic against incisional hernia. “So it’s really an off-label use. You’d be using your own clinical judgment,” Dr. Fischer said.

But researchers are homing in on risk stratification and patient identification tools that could eventually render PMA much less controversial. Five years ago, Dr. Fischer and his colleagues showed that a preoperative risk assessment could be used to predict which patients were more likely to develop an incisional hernia (Ann Surg 2016;263[5]:1010-1017).

“There are clearly high-risk patients who will develop hernias at a higher rate and sooner than others, and I think this was the first step into trying to figure out the patient populations this could happen to,” Dr. Hope said.

More recently, Dr. Fischer and his colleagues identified procedure-specific risk factors and developed an algorithm that can be used at the point of care to predict which patients might develop an incisional hernia (Ann Surg 2019;270[3]:544-553).

“Ultimately, this led to the Penn Hernia Risk Calculator, which is an app you can download to your smartphone and enter patient characteristics. This is something we can use quickly and easily in discussions with our patients about risk strategy and risk stratification, and I think it will go a long way to help surgeons,” Dr. Hope said.

“I’m not sure there will ever be a universal definition of what is high risk, but the calculator and support tools that are coming as we gain more information about risk factors are going to be really helpful,” he said.